Jenny 100, Robert Gault, Kaki's Sister and Jarkeld - thanks a lot for all the good information. I downloaded the Virtual PC program and may still get it up and running one of these days, because I do enjoy playing some of the older games. If so, I will likely be right back here asking for help.
In the meantime, I decided to try just one more QuickTime fix I'd come across, one that seemed too simple to work, but it did. Thought I'd post it here, just in case it might help someone else.
Install Myst. When it asks to install Quicktime, continue with the process, but SKIP the part where it searches for an older version of Quicktime.
That's all I did differently. Still don't understand why, but after trying a number of more complicated fixes - this did the trick.
Thanks again, everyone!